Questions regarding wiring 220 to attached garage...

Hi everybody and thanks for having me on the forum. I have been searching the internet and tapping some local sources for about 2.5 weeks now in regards to wiring 220 into my attached garage to run an air compressor. A few pertinent details are as follows:

With those details in place…I have a few questions as I am a novice and have never done any “new” wiring. I have replaced simple receptacles in the house without frying myself so I guess that is good but this serves to be a little bit more involved. Please do not feel as if you are going to offend me in any way by criticizing me….I am not a professional and I am here to get help so….PLEASE, lay it on me!

So here is the plan:I have an ‘old work’ box that I will use and run to the outside wall of the garage. I have a finished garage so, I will have a receptacle and plug configuration for the compressor. From there, I will run the conduit to the north sill where the main panel is. In this single run, there will likely be just at or around 365 degrees worth of turns so….we’ll see where the best LB/pull spot is but I think I have it mapped ok. At the end of the day…the run is not very long. My guestimation is about 30 ft of wire. So, my real question is termination of the pvc in the basement (unfinished) at the sill right above the panel. The ingress/egress hole in the sill if offset from the panel and is about a 4 ft run. Should I come in through the sill with a straight piece of PVC to an LB and then run NM wire and cap the wires inside the LB (junction), or should I run the wires straight shot into the panel with some PVC flexible conduit? Is is it preference? Is it legal per code? Also, would the LB box need to be secured to anything or is the PVC strength enough?